Nuclear Theory·nucl-th

Wednesday·May 1, 2019

7 papers—1 primary·6 cross-listed

02
[Submitted on 23 Apr 2019] (cross-list from hep-lat)
Magnetic catalysis and inverse catalysis for heavy pions
Gergely Endrodi🇩🇪 · Matteo Giordano🇭🇺 · Sandor D. Katz🇭🇺 · Tamas G. Kovacs🇭🇺 · Ferenc Pittler🇩🇪
We investigate the QCD phase diagram for nonzero background magnetic fields using first-principles lattice simulations. At the physical point (in terms of quark masses), the thermodynamics of this system is controlled by two opposing effects: magnetic catalysis (enhancement of the quark condensate) at low temperature and inverse magnetic catalysis (reduction of the condensate) in the transition region. While the former is known to be robust and independent of the details of the interactions, inverse catalysis arises as a result of a delicate competition, effective only for light quarks. By performing simulations at different quark masses, we determine the pion mass above which inverse catalysis does not take place in the transition region anymore. Even for pions heavier than this limiting value - where the quark condensate undergoes magnetic catalysis - our results are consistent with the notion that the transition temperature is reduced by the magnetic field. These findings will be useful to guide low-energy models and effective theories of QCD.
Comments:
Revised version; matches published version; 14 pages, 7 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1904.10296 [pdf]
JHEP(2019)·80 citations
03
[Submitted on 29 Apr 2019] (cross-list from hep-th)
Soft Bootstrap and Effective Field Theories
Ian Low🇺🇸 · Zhewei Yin🇺🇸
The soft bootstrap program aims to construct consistent effective field theories (EFT's) by recursively imposing the desired soft limit on tree-level scattering amplitudes through on-shell recursion relations. A prime example is the leading two-derivative operator in the EFT of $SU (N) \times SU (N) / SU (N)$ nonlinear sigma model (NLSM), where $O (p^{2})$ amplitudes with an arbitrary multiplicity of external particles can be soft-bootstrapped. We extend the program to $O (p^{4})$ operators and introduce the "soft blocks," which are the seeds for soft bootstrap. The number of soft blocks coincides with the number of independent operators at a given order in the derivative expansion and the incalculable Wilson coefficient emerges naturally. We also uncover a new soft-constructible EFT involving the "multi-trace" operator at the leading two-derivative order, which is matched to $SO (N + 1) / SO (N)$ NLSM. In addition, we consider Wess-Zumino-Witten (WZW) terms, the existence of which, or the lack thereof, depends on the number of flavors in the EFT, after a novel application of Bose symmetry. Remarkably, we find agreements with group-theoretic considerations on the existence of WZW terms in $SU (N)$ NLSM for $N \geq 3$ and the absence of WZW terms in $SO (N)$ NLSM for $N \neq = 5$ .
Comments:
41 pages + appendices, 13 figures; typos corrected in v3
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1904.12859 [pdf]
JHEP(2019)·65 citations
04
[Submitted on 29 Apr 2019] (cross-list from hep-th)
The complex life of hydrodynamic modes
Sašo Grozdanov🇺🇸 · Pavel K. Kovtun🇨🇦 · Andrei O. Starinets🇬🇧 · Petar Tadić🇮🇪
We study analytic properties of the dispersion relations in classical hydrodynamics by treating them as Puiseux series in complex momentum. The radii of convergence of the series are determined by the critical points of the associated complex spectral curves. For theories that admit a dual gravitational description through holography, the critical points correspond to level-crossings in the quasinormal spectrum of the dual black hole. We illustrate these methods in $N = 4$ supersymmetric Yang-Mills theory in 3+1 dimensions, in a holographic model with broken translation symmetry in 2+1 dimensions, and in conformal field theory in 1+1 dimensions. We comment on the pole-skipping phenomenon in thermal correlation functions, and show that it is not specific to energy density correlations.
Comments:
V3: 54 pages, 18 figures. Appendix added. Version to appear in JHEP
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); Mathematical Physics (math-ph); math.MP (math.MP); Nuclear Theory (nucl-th)
arXiv:
1904.12862 [pdf]
JHEP(2019)·179 citations
05
[Submitted on 29 Apr 2019] (cross-list from hep-ph)
Mapping the Kinematical Regimes of Semi-Inclusive Deep Inelastic Scattering
M. Boglione🇮🇹 · A. Dotson🇺🇸 · L. Gamberg🇺🇸 · S. Gordon🇺🇸 · J. O. Gonzalez-Hernandez🇮🇹 · A. Prokudin🇺🇸 · T. C. Rogers🇺🇸 · N. Sato🇺🇸
We construct a language for identifying kinematical regions of transversely differential semi-inclusive deep inelastic scattering cross sections with particular underlying partonic pictures, especially in regions of moderate to low $Q$ where sensitivity to kinematical effects outside the usual very high energy limit becomes non-trivial. The partonic pictures map to power law expansions whose leading contributions ultimately lead to well-known QCD factorization theorems. We propose methods for estimating the consistency of any particular region of overall hadronic kinematics with the kinematics of a given underlying partonic picture. The basic setup of kinematics of semi-inclusive deep inelastic scattering is also reviewed in some detail.
Comments:
37 pages, 11 Figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1904.12882 [pdf]
JHEP(2019)·54 citations
06
[Submitted on 29 Apr 2019] (cross-list from hep-ph)
Multiplicity dependence of strange and multi-strange hadrons in p $-$ p, p $-$ Pb and Pb $-$ Pb collisions at LHC energies using Tsallis-Weibull Formalism
Pritam Chakraborty🇮🇳 · Tulika Tripathy🇮🇳 · Subhadip Pal🇮🇳 · Sadhana Dash🇮🇳
The transverse momentum ( $p_{T}$ ) distribution of strange hadrons ( $K_{S}^{0}$ and $Λ$ ) and multi-strange hadrons( $Ξ$ and $Ω$ ) measured in p $-$ p, p $-$ Pb, and Pb $-$ Pb collisions at LHC energies have been studied for different multiplicity classes using Tsallis-Weibull (or q $-$ Weibull)formalism. The distribution describes the measured $p_{T}$ spectra for all multiplicity (or centrality)classes. The multiplicity dependence of the extracted parameters are studied for the mentioned collisions systems. The $λ$ parameter was observed to increase systematically with the collision multiplicity and follows a mass hierarchy for all collision system. This characteristic feature indicates that $λ$ can be associated to the strength of collectivity for heavy ion collisions. It can also be related to strength of dynamic effects such as multi-partonic interactions and color reconnections which mimic collectivity in smaller systems. The non-extensive $q$ parameter is found to be greater than one for all the particles suggesting that the strange particles are emitted from a source which is not fully equilibrated.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1904.12938 [pdf]
EPJA(2020)·2 citations
07
[Submitted on 30 Apr 2019] (cross-list from gr-qc)
On the change of old neutron star masses with galactocentric distance
Antonino Del Popolo🇮🇹 · Maksym Deliyergiyev🇵🇱 · Morgan Le Delliou🇨🇳 · Laura Tolos🇩🇪 · Fiorella Burgio🇮🇹
We show that the pulsar mass depends on the environment, and that it decreases going towards the center of the Milky Way. This is due to two combined effects, the capture and accumulation of self-interacting, non-annihilating dark matter by pulsars, and the increase of the dark matter density going towards the galactic center. We show that mass decrease depends both on the density profile of dark matter, steeper profiles producing a faster and larger decrease of the pulsar mass, and on the strength of self-interaction. Once future observations will provide the pulsar mass in a dark matter rich environment, close to the galactic center, the present result will be able to put constraints on the characteristics of our Galaxy halo dark matter profile, on the nature of dark matter, namely on its annihilating or non-annihilating nature, on its strength of self-interaction, and on the particle mass.
Comments:
30pp 2figs
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1904.13060 [pdf]
Phys.Dark Univ.(2020)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE

Magnetic catalysis and inverse catalysis for heavy pions

Soft Bootstrap and Effective Field Theories

The complex life of hydrodynamic modes

Mapping the Kinematical Regimes of Semi-Inclusive Deep Inelastic Scattering

Multiplicity dependence of strange and multi-strange hadrons in p−p, p−Pb and Pb−Pb collisions at LHC energies using Tsallis-Weibull Formalism

On the change of old neutron star masses with galactocentric distance

Affiliations

Multiplicity dependence of strange and multi-strange hadrons in p $-$ p, p $-$ Pb and Pb $-$ Pb collisions at LHC energies using Tsallis-Weibull Formalism